Study On Risk Factors And Risk Prediction Model Of PMV After CABG

Part 1 Risk factors associated with PMV following CABG-A Systematic Review and Meta-Analysis.Objective:To systematically evaluate the risk factors for prolonged mechanical ventilation after coronary artery bypass grafting.Methods:PubMed,EMBASE,Cochrane Library,Web of Science,ClinicalTrials.gov,CNKI,Wanfang and VIP were systematically searched for case-control studies or cohort studies on factors associated with prolonged mechanical ventilation following coronary artery bypass grafting.According to Cochrane system evaluation method,the quality of the research literatures meeting the inclusion criteria was evaluated.The adjusted odds ratios（OR）and 95%CI were extracted,and the RevMan5.3software was used for meta analysis.Results:Seven literatures were included in the study,including 5 203 patients.The correlation between prolonged mechanical ventilation following coronary artery bypass grafting and these factors was studied,including demographic factors:age,gender,body mass index,height,body weight;preoperative factors:left ventricular ejection fraction,chronic obstructive pulmonary disease,renal dysfunction,diabetes,unstable angina,preoperative IABP,EuroSORE,blood routine examination（WBC,HCT）,antiplatelet drugs（aspirin）;intraoperative factors:operative time,urgency of surgery（emergency surgery）,use of cardiopulmonary bypass,cardiopulmonary bypass time,intraoperative IABP,number of bypass,blood glucose,heart failure;postoperative factor:reoperation,postoperative IABP,blood transfusion,PaO₂/FiO₂ratio,perioperative complications（stroke,myocardial infarction）.Meta-analysis revealed:older age（OR=1.06,95%CI:1.05¹.07）,female（OR=1.92,95%CI:1.37².68）,lower left ventricular ejection fraction（OR=0.97,95%CI:0.95⁰.99）,renal dysfunction（OR=2.35,95%CI:1.41³.90）,longer operative time（OR=1.50,95%CI:1.22¹.85）,reoperation（OR=9.56,95%CI:3.65²5.00）are the independent risk factors for prolonged mechanical ventilation after coronary artery bypass grafting.There is insufficient evidence to confirm the correlation between other factors and prolonged mechanical ventilation after coronary artery bypass grafting,including body mass index（OR=0.95,95%CI:0.68¹.32）,chronic obstructive pulmonary disease（OR=3.94,95%CI:0.68²2.81）,height,body weight,unstable angina,preoperative IABP,EuroSORE,blood routine examination（WBC,HCT）,antiplatelet drugs（aspirin）,urgency of surgery（emergency surgery）,use of cardiopulmonary bypass,cardiopulmonary bypass time,intraoperative IABP,number of bypass,blood glucose,heart failure,postoperative IABP,blood transfusion,PaO₂/FiO₂ ratio,perioperative complications（stroke,myocardial infarction）.Conclusion:older age,female,preoperative lower left ventricular ejection fraction,preoperative renal dysfunction,longer operative time and reoperation are the independent risk factors for prolonged mechanical ventilation after coronary artery bypass grafting.This study provides theoretical support for the prevention and risk prediction model of prolong mechanical ventilation after coronary artery bypass grafting.Part 2 Risk prediction model for PMV after OPCABG in single-centerObjective:To construct a risk prediction model for prolonged mechanical ventilation（PMV）after off-pump coronary artery bypass grafting（OPCABG）in single-center,and to evaluate the predictive performance for PMV after OPCABG compared with the American Society of Thoracic Surgeons（STS）risk evaluation system.Methods : The clinical information of 110 patients undering OPCABG were retrospectively analyzed.The patients were divided into non-PMV group（mechanical ventilation time ≤24h）and PMV group（mechanical ventilation time>24h）.The risk factors of PMV was established by Univariate analysis and binary logistic regression analysis.The area under the receiver operating characteristic（AUC）was used to assess model discrimination,and the calibration was assessed by the Hosmer-Lemeshow（H-L）statistics and observation versus expected（O:E）.Results:There were 28 cases of PMV in the entire cohort,and the realized rate was25.45%.Lower height（OR=0.932,95% CI: 0.876⁰.991）,COPD（OR=18.894,95%CI: 3.410¹04.678）,preoperative arrhythmia（OR=4.645,95% CI: 1.430¹5.086）were independent risk factors for PMV after OPCABG.The PMV risk prediction model achieved good discrimination in the entire cohort（AUC=0.770>0.75）,the discrimination of the high-risk group was acceptable（AUC=0.733>0.70）,and the discrimination of the low-risk group was poor（AUC=0.592<0.70）;It achieved good calibration in both entire cohort（O: E = 0.999）and high-risk group（O: E = 1.113）,while the rate of PMV was overestimated in the low-risk group.The STS risk evaluation system achieved acceptable discrimination the entire cohort（AUC=0.736>0.70）,and the calibration was poor（O:E=3.615）,which seriously underestimated the rate of PMV in the entire cohort;The discrimination were poor in low-risk group（AUC=0.614<0.7）and high-risk group（AUC=0.567<0.7）,which the rates of PMV were seriously underestimated in both groups.Conclusion:The PMV risk prediction model can be used to predict the risk of PMV after OPCABG in the entire cohort and high-risk group,whereas The STS risk evaluation system is not suitable temporarily for the risk assessment of PMV after OPCABG in our center.